Grinding apparatus and clutch therefor



H. A. CHASE. GRINDING APPARATUS AND CLUTCH THEREFOR. APPLICATION FILED MAR. 11, 1920.

3 SHEETSSHEET I.

Patented Mar. 22, 1921.

H. A. CHASE. GRINDING APPARATUS AND CLUTCH THERE FOR.

APPLICATION FILED MAR. 11, 1920- Patented Mar. 22, 1921.

3 SHEETS-SHEET 2- H. A. CHASE.

GRINDING APPARATUS AND CLUTCH THEREFOR. APPLICATION FILED MAR.1I, 1920.

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UNlTED STATES PATENT OFFICE.

GRINDING APPARATUS AND CLUTCH THEREFOR.

Specification of Letters Patent.

Patented Mar. 22, 1921.

Application filed March 11, 1920. Serial No. 364,974.

To all whom it may concern:

Be it known that I, HENRY A. CHASE, a citizen of the United States, and resident of Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Grinding Apparatus and Clutches Therefor, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My present invention is an improved and novel machine for grinding work, particularly valves, valve stems, cutters, and the like, where a predetermined angle or bevel is to be operated upon.

7 Important objects of the invention are to novel, efficient and com-- pact grinding machine capable of acting quickly upon the work and at an angle with the grinding medium, together with means whichwill enable the grinding action to be performed on the face of the grinding medium as distinguished from its edge.

Other important features of the present invention consist in means to adjust the work holding devices at any predetermined angle, means to effect a relative movement between the grinding medium and the work, and in a manner to effect a constant truing action, preventing the grinder from wearing down along a single line or point; means to so arrange the face of. the grinder and the work as to secure a self-cleaning or clearing action; and means to effect a quick attachment and detachment of the work to the work holding devices.

In order to quickly secure and hold the work to the work holder, I have devised a novel form of clutching mechanism which will enable the work-such as a valve for automobile engines-01 other device having a shaft or stem-to be instantly, securely and accurately clutched to a rotatable wheel or member, so that the work can be turned at such speed as is desired during the grinding operation. I have also provided novel means to secure a rigid, firm, and truly ground bearing to center the work in its clutch, together with means to hold the clutch and work engaged thereby into a firm bearing contact with a bearing which is ground to an exact perpendicular plane with the axis of rotation.

Other features of the invention, novel combinations of parts and advantages will be hereinafter more fully pointed out and claimed.

Referring to the drawings illustrating a preferred embodiment of the invention,

F gure 1 is a side view, partly in crosssect on, illustrating the machine;

Fig. 2 is a plan view on an enlarged scale;

Fig. 3 is a cross-sectional view through a part of the clutch and working holding portions of the work holder; and

Fig. 4 is a cross-section on the line 4-4 of Fig. 3.

My machine is preferably made in the form of a small compact bench machine but it will be readily understood that the same can be of any suitable size or power. As

herein illustrated, the machine is organized primarily to grind, at a predetermined bevel, the seating surfaces of the tappet or puppet valves in automobile engines. As these valve seats are usually made of extremely hard and tough alloy, such as tungsten or vanadium steel it has been exceedingly diiiicult to form, grind or regrind the same under the old methods. Prior methods have usually consisted in simply grinding these surfaces against the edge of an emery orcarborundum grinding whee which was .rapidly rotated. It was also necessary to grind and regrind the valve seats and at exactly the same angle or bevel as that formed on the tappet valves, in or der that a substantially perfect mechanical fit might be secured. My machine is capable of not only grinding the valves accurately, but also of grinding and truing the cutters to ream the valve seats accurately. In fact, my invention contemplates the pro vision of means to reproduce any desired angle or bevel on cooperating tools or surfaces, and by effecting this grindin action between relatively moving the broad side or face of the grinding medium and the work. By thus employing the side of a grinding wheel, greater wear is possible, the grinding medium is maintained in alinement and with a substantially true grinding face or lane and the grinding action occurs along a line as distinguished from a point or edge, so that both grinder and work are automatically trued up in the plane of the desired bevel.

Referring to the drawings, 1 represents a suitable base or stand in which a motor 2 is mounted, a driving pulley 3 being secured to cured to the underside post 10 carries a. lateral arm 56 and an upthe shaft 4 of the motor. base 1, as shown at 5, has a recess 6 through which a belt 7 is led from the pulley 3 upwardly to the ulleys to be described, which rotate the Wor and grinder. In the top 5, also, is formed a recess 9, and to receive the post 10 which supports the work holder to be described. A pair of lugs 12 and 14 on the upper surface of the top 5 constitute bearings for the shaft 15 on *hich the grinding medium may be oscillated. Also a rigid post 20 extends from the top upwardly, carrying at its uppermost portion a journal bearing 21 in which a shaft 22 is fitted. On one outer end of this shaft 22, at the left viewing Fig. l, is secured a pulley 23, around which the belt 7 from the motor pulley 3 is led, thus imparting power from said motor to the shaft 22. A second pulley 24 is also keyed on said shaft and a third pulley 25. Power is supplied from these pulleys 24 and 25 to the work holding devices and grinding medium respectively.

I prefer to mount the grinding medium, here shown as an emery disk 31). at a convenient height above the table 5 and in a manner to be rocked or oscillated. For this purpose I secure to the shaft 15, which is journaled in the lugs 12 and 11, a hub 31, from which extends an arm 32. having in its uppermost portion a pair of journal bearings 33 and 34, in which a shaft 35 is fitted, on which the emery wheel 30 is mounted, being held between the nut or bolt 36 and a washer 37. Mounted on the shaft 35 is a pulley 40, having its hub 41 secured to said shaft by a set screw 42. Suitable grease cups 43 and 44 are also provided for the bearings of this shaft. Power is supplied to rotate the emery wheel 30 through this pulley 40 by a belt 46 extending over the pulley 40 and the upper power driven pulley 25. These pulleys are respectively so proportioned as to impart a high speed of rotation to the emery or carborundum Wheel 30. Secured to one end of the shaft 15 is a handle 50 adapted to oscillate the emery wheel on the rockshaft 15 during the rotation of the emery wheel. In order to afford a fine adjustment of the wheel toward or from the work, I mount on the top 5 of the base a post 51. threaded to receive the correspondingly threaded shank 52 of an adjusting screw 53, having the end of said shank bear ing against the axis of the shaft 15. as clearly shown in Fig. 2. This also resists the natural thrust of the operator in actuation of the handle 50 during the oscillation of the emery wheel to and fro across the work.

The work holder, as already noted. is rotatably mounted on the post 10 titted within a socket therefor illustrated as a block 55 seof the top 5. This The top of the wardly extending portion 57, terminating in a head 58 which is bored as shown at 59 to receive a rotatable shaft 60. The head 58 has forwardly extending forked portions (31 and 62, each being vertically bored to receive adjustable guides 63 and 64 respectively, the upper guide having its lower face beveled at 65 as shown in Fig. 4, and these guides or adjustable bearings are secured in desired adjusted position by set screws 66 and 67 threaded through correspondingly threaded tapped recesses in the forks (51 and 62.

The lateral arm 56 also has an upwardly extending portion 68, and a plate 70 having a plurality of recesses 71, 71, to receive a post 72 constituting rearward guide for the work. Set screws 73 and 73 hold said post in desired position in the recesses 71, 71. The sleeve 74 is also secured to the post 72 by a set screw 75, said sleeve having an opening or recess therethrough as shown at T6. and carries in its upper part a cooperating guide or hearing 80, adjustably secured thereto by a set screw 79, as clearly shown in Fig. 3. This movable and adjustable rear bearing is to act as a steady rest and guide for varying lengths of valve stems or other work holding devices fitted within the work holder.

Fitted within the head 58 is the sleeve (30 rotatable therein and carrying a pulley S1 rigidly secured by a key 82 thereto. This pulley receives its power by means of a belt %3 to the power driven pulley 24. on the shaft 22. The sleeve 60 has a rearwardly extendmg run 85, and a ground face 86 against which a washer 87 is positioned, being held in contact with the ground face 86 of the member 60 by a pressure of a spring 88. against a washer 89 which latter in turn bears against the cupped washer 90 on the rear of the clutch ball 100. The washers 9 and 90 are each cup shaped, having rccesses as shown at 91, 91. in which the ball clutch member rests, both washers and ball being bored of greater diameter than the valve stem or work to be handled. Tapped through the ball clutch 100 is a set screw 92 extending through a recess 93 in the ring portion 85 of the rotatable member 60. Preferably also I form the member 60 with its rearwardly extending open ring 85 with a shoulder 95 adapted to bear directly against the rim of the head 58. thus constituting a firm, rigid, and accurately ground bearing for the member 68 and the continuous rotation of the wheel 81. A spring 88 acts to keep. the set of washers and ball in firm contact with the face 86 of the rotatable member 60 and this insures a. true and accurate rotation thereof. This construction also enables the valve stem 101 to he quickly fitted through the rotatable member (50 and secured to the ball clutch thus ground removed,

100, these accurately holding and firmly and rigidly alining the same against the face 86 and rotating the valve seat 102 in axial alinement with the wheel 81. It is important in a machine of this character to have a clutch which will quickly engage the work and be quickly disengaged therefrom, to speed up production, and which will also accurately hold, center and rotate the work. My mechanism comprises such devices and enables tioned, clutched and with thesteady rests 63 and 6 1 at the front end and 72 and 80 at the rear stem of the valve stem 100 adjusted for bearing and holding the same against undue strains, the instantaneous release and tightening of the thumb nuts effecting this result. The fitting in of the valve stem 101 can be made by allowing the valve seat 102 to rest against the grinding surface 103 of the grinder 30, whereupon the thumb nut 92 is tightened and the valve clutched to the rotatable member and the wheel 81. The spring 88 may be forked, as illustrated in Fig. 2, and thus still further enable the washers and valve ball tobe auto-- matically seated against the bearing face 86. The operation of the apparatus will be readily understood. With the motor at rest, the operator applies the valve stem 101 of a valve into position, sliding it through the hollow rotatable member 60 until the valve face 102 comes in contact withthe face of the grinder 103, the grinder being oscillate/d through the valve stem by manipulation of the handle 50 for this purpose, if necessary. Thereupon the valve stem 101 is clutched to the rotatable member 60, the motor energized and the rotation of the valve seat and grinder begun. The entire work holder may be adjusted for the desired angle to be ground, or if the reproduction of a predetermined angle is desired, the work holder is left at the angle formerly made, so that the-valve seat 102 and the face of the grinder 30 will he in exact angular relation. Thereupon the operator slowly oscillates the rock shaft 15 by swinging the handle 50 to and fro, thus causing the entire face of the grinder 103 to traverse the surface 102 of the valve, which latter is also rapidly rotat ing. The swinging and slanting cutting action between the grinder and the valve seat also automatically effects a truing or even wearing away of the grinder, keeping its face at all times in an accurate vertical plane. The action also effects a clearing of the ground material from clogging the face of the grinder, leaving the grinding surface clean, clear and in cutting condition. But a few manipulations of the grinding medium are required to effectually regrind the entire surface of the valve face. There upon the motor can be stopped, the valve and another one posi:

the valve stem to be qulckly positioned and reground to exactly the same angle. Or if desired the reaming cutter esired to grind the valve seat can be positioned and the cutting surface of the reamer be ground to exactly the bevel which has just been formed on the valve. Various angular adjustments can be made as desired and any predetermined speed or direction of rotation of the respective members can be made. I consider that the entire grinding machine assembled to effect a predetermined bevel grinding on the face of a cutter and in a manner to keep the same automatically trued or in its desired plane, is-a distinct novelty, and also that my quickly detachable and centering clutch is an important novelty and I wish to claim these features broadly.

It will be appreciated that my quick acting clutch will run true and will automatically center itself upon the broad ground bearing face 86, irrespective of the wear or diameter of the shank or stem of the valves being ground. In practice these valve stems *ear considerably, and therefore my clutch constitutes automatic means to compensate for such wear, and this feature is important in devices of this kind.

My invention is further, described and defined in the form of claims as follows:

1. Apparatus of the kind described, comprising a work holder, a grinding medium, and means to rotate it, means to adjust the work holder at an angle with the axis of rotation of said grinding medium, and means to detachably clamp work in said work holder, together with means to adjust the grinder longitudinally for contact with the work in said work holder.

2 Apparatus of the kind described, comprising a work holder, a rotatable clamp in said work holder adapted to hold and rotate work therein, a pivotal carrier for the grinding disk, means to rotate said grinder, while permitting oscillation of the carrier on its pivot, whereby work held in said work holder may be brought intermittently into contact with the grinding medium by the oscillation of said grinding medium on its carrier.

3. Apparatus of the kind described, comprising a grinding disk, a work holding member positioned at an angle to said grinder, a fixed bearing for the rotating portion of said work holder, a cup-shaped washer, in contact with said bearing, a work holding clamp resting in said cup shaped washer and means to hold said work holding clamp yieldingly in contact with the washer during the rotation of the work.

4. Apparatus of the kind described, comprising a grinding disk, a work holding member positioned at an angle to said grinder, a fixed bearing for the rotating portion of said work holder, a cupshaped washer, in contact with said bearing, a work at an angular position relatively with the 15 holding ball resting in said cup sha ed grinding medium, comprising a. pivotal Washer and means to hold said Work hol ing mounting for the work holder, a hollow roball yieldingly in contact with the washer tatable member adapted to receive the stem during the rotation of the work. of valves or the like, a pulley keyed to said 5. A clutch member, comprising a hollow rotatable member, aball clamp carried bythe 20 ball, adapted to receive work therethrough, member and held in contact therewith by means to secure the ball to the work, and yielding means, and means to attach the means to provide a fixed rigid bearing for work to said ball clamp, in combination with the ball, said bearing being free of Contact adjustable steady rests for the work. With the Work, whereby work of varying In testimony whereof, I have signed my 25 sizes can be attached to the ball clamp. name to this specification.

6. A rotatablework holder for holding tappet valves, reamers, grinders or the like HENRY A. CHASE. 

